This invention generally relates to electrical communication devices and more particularly to devices for transmitting an electrical signal from a condition monitoring sensor mounted on a first member moving rotationally relative to a signal detector mounted on a second member. While in its broadest scope the invention may be applied to other fields, it is herein specifically described with respect to aircraft applications wherein it is desired to transmit pressure, temperature, and/or speed information signals from a rotating wheel to an electronic detector mounted on the landing gear strut. The signals of interest are ultimately transmitted to the cockpit via the aircraft wiring for pilot observance of an indicated condition.
The term "signal communicator" as used herein is broadly defined and is a device that functions as a mechanical coupler, contactor, or interconnector for conveying, passing, or transmitting an electrical signal between two members, one of the members moving relative to the other member.
In the field of monitoring for a sensed condition occurrence on a first member moving rotationally with respect to a second member, the interface between the two relatively moving members has always posed a particular problem. Solution of the problem in some applications involved elaborate mechanical configurations of carbon brushes contacting rotating armatures and in other applications it involved electrical coupling techniques including inductive, capacitive, and/or impedance coupling configurations. While these techniques have met with some success in various limited applications, they have not been altogether successful in the aircraft environment wherein extremes of pressure, temperature, and/or corrosion are experienced. In an aircraft application and other similar type applications wherein public safety are a matter of concern, it is not only important that the primary apparatus and equipment function reliably, but it is equally important that the devices which monitor such operation function reliably. To this end, the present invention provides a signal communicator that is substantially insensitive to the environment, simple in operation, compact, failsafe, and exhibits long wear and reliability over its intended life expectancy.